What do the signs mean? Use must/mustn’t:
- No smoking: You must not smoke here.
- Sorry! No animals Thank you: You must not bring animals here.
- Keep dogs on leads: You must keep dogs on leads.
- Keep Left: You must keep to the left.
- No cycling in the gardens: You must not cycle in the gardens.
- Clean up after your dog: You must clean up after your dog.
Explanation: 'Must not' is used for prohibitions (things you are forbidden to do), and 'must' is used for strong obligations (things you have to do).